Chemical constituents of Cinnamomum cebuense.

AIM: To investigate the chemical constituents of Cinnamomum cebuense, an endemic and critically endangered tree found only in Cebu, Philippines. METHODS: The compounds were isolated by silica gel chromatography. The structures of the isolates were elucidated by NMR spectroscopy. RESULTS: The dichloromethane (DCM) extract of the bark of C. cebuense afforded a new monoterpene natural product 1 and a new sesquiterpene 2, along with the known compounds, 4-hydroxy-3-methoxycinnamaldehyde (3), 4-allyl-2-methoxyphenol (4), α-terpineol (5) and humulene (6). The DCM extract of the leaves of C. cebuense yielded 6, ß-caryophyllene (7), squalene (8), and a mixture of α-amyrin (9), ß-amyrin (10) and bauerenol (11). The structures of 1-7 were elucidated by extensive 1D and 2D NMR spectroscopy, while the structures of 8-11 were identified by comparison of their (13)C NMR data with those reported in the literature. CONCLUSION: The bark of C. cebuense afforded monoterpenes, sesquiterpenes and phenolics, while the leaves yielded sesquiterpenes and triterpenes.

Hypoglycaemic effects of tea extracts and ent-kaurenoic acid from Smallanthus sonchifolius.

Hypoglycaemic activity was observed in normoglycaemic mice orally administered with the aqueous Smallanthus sonchifolius leaf tea extract, alloxan-induced diabetic mice orally administered with ent-kaurenoic acid (1), and normoglycaemic mice intraperitoneally administered with 1 from S. sonchifolius leaves. A single dose administration of 50 mg kg(-1) BW yacon leaf tea extract demonstrated immediate but relatively short hypoglycaemic activity, with significant effects observed during 1-2 h. Similarly, administration with 100 mg kg(-1) BW yacon leaf tea extract obtained by heavy stirring in hot water demonstrated a more potent activity compared to the positive control at 1.5-2.0 h. Oral administration of 1 did not affect the blood glucose level of the alloxan-induced diabetic mice, but a single intraperitonial injection of 10 mg kg(-1) BW in normoglycaemic mice had consistent percent blood glucose reduction persisting from 1 to 2 h observation periods.